The subject invention concerns improvements in concrete blocks designed to serve as road barriers, and roadway or lane defining members. The blocks have an elongate concrete body with an essentially triangular cross-sectional shape including one bottom face and two preferably symmetrical side faces.
In four-lane traffic routes median barriers and roadway defining members are often used to prevent vehicles travelling in one direction from entering the lanes in which the vehicles are moving in the opposite direction. In case of accidents caused by skidding, aqua-planing, tyre punctures or careless driving such road barriers may prevent the vehicles involved in the accidents from colliding head-on with oncoming traffic.
The barriers and roadway defining means usually consist of concrete plinths to which horizontal steel beams are attached. One disadvantage with barriers and roadway defining members of this kind is that the steel material of the beams make them somewhat resilient, with the result that vehicles colliding with the barrier at an oblique angle of impact as a rule will be thrown back towards the vehicles travelling in a direction parallel with that of the colliding vehicle, or even be thrown off the road. A comparatively harmless accident therefore may have very serious consequences.
Road barriers of the kind referred to above are permanently anchored, that is, they cannot be opened up to allow the traffic to be rerouted onto adjoining traffic lanes in case one lane or roadway is blocked off. Nor is it possible to use this kind of road barriers to protect workmen engaged in temporary road work.
It is also known to use concrete blocks as median barriers to separate opposing traffic roadways. The blocks have a triangular cross-sectional shape and may be moved temporarily to divert traffic in case of accidents and may also be used as protection during road work. Cases have been reported, however, when as a result of aqua-planing or skidding, vehicles hit a row of concrete blocks at an acute angle and roll over the blocks and onto the lane of oncoming traffic, thus causing serious accidents. Also when vehicles hit the concrete blocks at low speeds the damages to the front part of the car chassis have proved to be so serious that the car has to be towed from the place of accident and be repaired at great expense.
The purpose of the road block in accordance with the subject invention is to prevent vehicles hitting the barriers from rolling over the barriers, from being thrown into the lane of parallel traffic or from being damaged to such an extent that the vehicle must be towed away. The road block is furthermore intended for use in temporary road work. It is also designed to allow individual, damaged blocks to be easily replaced, to allow water runoff, and to be rapidly and easily dismantled and removed for asphalting and other paving work or when an opening is desired through the barrier. The block in accordance with the invention furthermore serves as a blind, screening off glaring and blinding lights from oncoming traffic. In addition, it is designed to allow road signs, lights poles and noise-reducing mats to be mounted thereon.